Window-jack



("No Model.) 2 sheets -sheet 1'.

M. PRE'NDERGAST. WINDOW JACK.

No.5'03.,21'7. Patented Aug.'15,1893.

WWII

(No Model.) 2 SheetsShet 2.

M. PRENDERGAST. WINDOW JA;0K.,

No. 503,217; V Patented Aug. 15, 1893;

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UNITED STATES PATENT OFFICE.

MICHAEL PRENDERGAST, OF CHICAGO, ILLINOIS.

WINDOW-JACK.

SPECIFICATION forming part of Letters Patent No. 503,217, dated August 15, 1893.

Application filed NovemberlQ, 1892. filerialNo. 452,617. (No model.)

To all whom it may concern.-

Be it known that I, MICHAEL PRENDER- GAST, of Chicago, Illinois, have invented certain new and useful Improvements in Win dow-Jacks, of which the following is a specification.

This invention has relation to certain improvements in window jacks; and the object of the invention is to provide a window jack which can be readily adapted to any window.

. My improved window jack comprises a platform, the inner end of which is adapted to rest upon the window stool, and the outer end of which projects beyond the line of the wall to afford room for a person to stand thereon in cleaning windows or for any other purpose; movable blocks which rest on the window ledge and support the platform in a horizontal position; and a pair of bars movably secured to the inner end of the platform,

and which bars can be adjusted as to length so as to adapt their ends to engage the inner sides of the window frame to hold the device in place.

WVindows vary greatly in width, and they also vary considerably as to the thickness of the sill of the window frame and as to the pitch or inclination of the ledge. My invention adapts the window jack to all of these variations of construction and furnishes a safe and efficient device.

In the accompanying drawings, Figure l is a perspective view showing the window jack applied. Fig. 2 is a plan view of the jack; and Fig. 3 is a cross section through the platform and blocks.

4 represents the platform of the jack, which is made of one or more planks of suitable thickness and length, and which is provided with the pin holes 5.

6 represents blocks which are beveled on their under sides and are connected by the brackets *7 to the cleat 8, forming ways in which the platform rests. The brackets and cleat have transverse apertures near the outer ends of'the cleat and the pins 9 pass through these apertures into the pin holes of the platform and prevent the movement of the blocks after they have been adjusted so as to bring the platform to a horizontal position. To the inner end of the platform are secured the stirrups 10 in which are mounted so as to slide freely upon each other thebars 11. These bars are preferably stout oak timbers, two by four inches in dimension, and of a suitable length, so that when extended as shown in Fig. 1, they are adapted to hold the jack in position in a wide window, and when shoved together as shown in Figs. 2 and 3, they occupy less space and better adapt the dvice for use with a narrower window.

The manner of using the window jack will be understood from the drawings; and the abovedescription shows its adaptability to varying circumstances.

I claim- The herein-described window jack comprising a fiat platform provided with a series of pin holes in line with its side edges, and with stirrups at its end whose openings are in line with the end of the platform, beveled blocks adapted to rest on the window ledge, brackets connected to said blocks and extending above the plane of the platform, a cleat extending transversely above the platform and secured with the brackets and provided with pin holes to register with those of the platform, pins to secure the cleat in position and bars passing through the stirrups and adapted to slide upon each other and to be adjusted to the window, substantially as described.

MICHAEL PRENDERGAST.

Witnesses:

FREDERICK O. GooDwIN,

N. M. BOND. 

